A California state university is investigating comments made on Twitter by an English professor who called Barbara Bush an “amazing racist” shortly after the former first lady's death Tuesday at age 92.

“Barbara Bush was a generous and smart and amazing racist who, along with her husband, raised a war criminal,” Randa Jarrar wrote on Twitter.

"Many of us had no idea who @randajarrar was at first & assumed she was just another rather nasty person on Twitter," wrote one who addressed Castro. "Imagine our surprise when we found out she represents your institution. You may want to get ahead of this."

Fresno State issued a statement from Castro that extended condolences to the Bush family on the loss of the former first lady.

"We share the deep concerns expressed by others over the personal comments made today by professor Randa Jarrar, a professor in the English Department at Fresno State," Castro wrote. "Her statements were made as a private citizen, not as a representative at Fresno State."

After people began to criticize her in online posts, Jarrar responded that she was protected from being fired because she has tenure at the university, the Fresno Bee reported.

Castro on Wednesday called Jarrar’s comments disrespectful and said they went beyond free speech, the newspaper reported.

“A professor with tenure does not have blanket protection to say and do what they wish,” Castro said. “We are all held accountable for our actions.”

Jarrar, who is on leave this semester, describes herself in her Twitter messages as an Arab-American and a Muslim-American woman.

Abre Conner, a staff attorney for ACLU Northern California, said Jarrar’s statements fall under her First Amendment rights to express a political opinion on her own time.

“If Fresno State administrators are reviewing her based on this political speech, that is troubling,” he said.

Jarrar was scheduled to appear at an event titled "LitHop" this weekend, but the event’s organizers and Fresno City College said she told them she will not participate.